Dysrythmias Questions and Answers
A+ Graded (2025)
PR .interval. .
Rationale: .The .PR .interval .represents .depolarization .of .the .atria, .AV .node,
.bundle .of .His, .bundle .branches, .and .the .Purkinje .fibers, .up .to .the .point .of
.depolarization .of .the .ventricular .cells. .- .CORRECT .ANSWER-In .analyzing .a
.patient's .electrocardiographic .(ECG) .rhythm .strip, .the .nurse .uses .the .knowledge
.that .the .time .of .the .conduction .of .an .impulse .through .the . Purkinje .fibers .is
.represented .by .the
use .the .3-second .markers .to .count .the .number .of .QRS .complexes .in .6 .seconds
.and .multiply .by .10.
Rationale: .This .is .the .quickest .way .to .determine .the .ventricular .rate .for .a .patient
.with .a .regular .rhythm. .- .CORRECT .ANSWER-When . needing .to .estimate .the
.ventricular .rate .quickly .for .a .patient .with .a .regular .heart . rhythm .using .an .ECG
.strip, .the .nurse .will
40-60 .
If .the .SA .node .fails .to .discharge, .the .junction .will .automatically .discharge .at .the
.normal .junctional .rate .of .40 .to .60. .- .CORRECT .ANSWER-A .patient .has .a
.junctional .escape .rhythm .on .the . monitor. .The .nurse .would .expect .the .patient .to
.have .a .pulse .rate .of .____ .beats/min.
Obtain .further .information .about .possible .causes .for .the .heart .rate.
Rationale: .The .patient .has .sinus .tachycardia, .which .may .be .caused .by .multiple
.stressors .such .as .pain, .dehydration, .or .myocardial .ischemia; .further
.assessment .is .needed .before .determining .the .treatment. .- .CORRECT .ANSWER-
A .patient .who .is .complaining .of .a ."racing" .heart .and .nervousness .comes .to .the
.emergency .department. .The .patient's .blood .pressure .(BP) .is .102/68. .The .nurse
.places .the .patient .on .a .cardiac .monitor .and .obtains .the .following .ECG .tracing. .
Which .action .should .the .nurse .take .next?
MCL1
Rationale: .Leads .II .and .MCL1 .are .the .best .leads .for .visualization .of .P .waves,
.which .reflect .atrial .activity. .- .CORRECT .ANSWER-A .patient .has .a .dysrhythmia
.that .requires .careful .monitoring .of .atrial .activity. .Which .lead .will .be .best .to .use
.for .continuous .monitoring?
,ventricular .tachycardia.
Rationale: .The .absence .of .P .waves, .wide .QRS, .rate .>150, .and .the .regularity .of
.the .rhythm .indicate .ventricular .tachycardia. .- .CORRECT .ANSWER-The .nurse
.obtains .a .monitor .strip .on .a .patient .admitted .to .the .coronary .care . unit .with .a
.myocardial .infarction .and .makes .the .following .analysis: .P .wave . not .apparent;
.ventricular .rate .162, .R-R .interval .regular; . PR .interval .not .measurable; .and .QRS
.complex .wide .and .distorted, .QRS .duration .0.18 .second. .The .nurse .interprets .the
.patient's .cardiac .rhythm .as
every .other .QRS .complex .is .wide .and .starts .prematurely.
Rationale: .Ventricular .bigeminy .describes .a .rhythm .in .which .every .other .QRS
.complex .is .wide .and .bizarre .looking. .- .CORRECT .ANSWER-The .nurse
.determines .that .a .patient .has .ventricular . bigeminy .when .the .rhythm .strip
.indicates .that
document .the .finding .and .continue .to .monitor .the .patient
.Rationale: .First-degree .atrioventricular .(AV) .block .is .asymptomatic .and .requires
.ongoing .monitoring .because .it .may .progress .to .more .serious .forms .of .heart
.block. .- .CORRECT .ANSWER-A .patient .has .a .normal .cardiac .rhythm .strip .except
.that .the .PR .interval .is .0.34 .seconds. .The .appropriate .intervention .by .the . nurse .is
.to
hypokalemia.
Rationale: .Hypokalemia .increases .the .risk .for .ventricular .dysrhythmias .such .as
.PVCs, . ventricular .tachycardia, .and .ventricular .fibrillation. .- .CORRECT .ANSWER-
A .patient .with .diabetes .mellitus .is .admitted .unresponsive .to .the .emergency
.department .(ED). .Initial .laboratory .findings .are .serum .potassium .2.8 .mEq/L .(2.8
.mmol/L), .serum .sodium .138 .mEq/L .(138 .mmol/L), .serum .chloride .90 .mEq/L .(90
.mmol/L), .and .blood .glucose .628 .mg/dl .(34.9 .mmol/L). .Cardiac .monitoring .shows
.multifocal .PVCs. .The .nurse .understands .that .the .patient's .PVCs .are .most .likely
.caused .by
administer .IV .antidysrhythmic .drugs .per .protocol.
Rationale: .The .burst .of .sustained .ventricular .tachycardia .indicates .that .the
.patient .has .significant .ventricular .irritability, .and .antidysrhythmic .medication
.administration .is .needed .to .prevent .further .episodes. .- .CORRECT .ANSWER-The
.nurse .reviews .data .from .the .cardiac .monitor .indicating .that .a .patient .with .a
.myocardial .infarction .experienced .a .50-second .episode .of .ventricular
.tachycardia .before .a .sinus .rhythm .and .a . heart .rate .of .98 .were .re-established.
.The .most .appropriate .initial .action .by .the . nurse .is .to
third-degree .AV .block.
Rationale: .The .inconsistency .between .the .atrial .and .ventricular .rates .and .the
.variable .PR .interval .indicate .that .the .rhythm .is .third-degree .AV .block. .-
.CORRECT .ANSWER-A .patient .experiences .dizziness .and .shortness .of .breath .for
.several .days. .During .cardiac .monitoring .in .the .ED, .the .nurse .obtains .the
.following .ECG .tracing. .The .nurse .interprets .this .cardiac .rhythm .as
increase .in .the .patient's .heart .rate.
, Rationale: .Atropine .will .increase .the .heart .rate .and .conduction .through .the .AV
.node. .- .CORRECT .ANSWER-A .patient .with .myocardial .infarction .develops
.symptomatic .hypotension. .The .monitor .shows .a .type .1, .second-degree .AV .block
.with .a .heart .rate .of .30. .The .nurse .administers .IV .atropine .as .prescribed. .The
.nurse .determines .that .the .drug .has .been . effective .on .finding .a(n)
anticoagulant .therapy .with .warfarin .(Coumadin).
Rationale: .Atrial .fibrillation .therapy .that .has .persisted .for .more .than .48 .hours
.requires .anticoagulant .treatment .for .3 .to .4 .weeks .before .attempting
.cardioversion; .this .is .done .to .prevent .embolization .of .clots .from .the .atria .-
.CORRECT .ANSWER-A .patient .with .dilated .cardiomyopathy .has .an .atrial
.fibrillation .that .has .been .unresponsive .to .drug .therapy .for .several .days. .The
.nurse .anticipates .that .further .treatment .of .the .patient .will .require
start .basic .cardiopulmonary .resuscitation .(CPR).
Rationale: .The .patient's .rhythm .and .assessment .indicate .ventricular .fibrillation
.and .cardiac .arrest; .therefore, .the .initial .actions .include .calling .for .help, .and
.initiating .CPR .until .defibrillation .is .possible. .- .CORRECT .ANSWER-The .nurse
.hears .the .cardiac .monitor .alarm .and . notes .that .the .patient .has .a .cardiac .pattern
.of .undulations .of .varying .contours .and .amplitude .with .no .measurable .ECG
.pattern. .The .patient .is .unconscious .with .no .pulse .or .respirations. .After .calling
.for .assistance, .the .nurse .should
apical .radial .heart .rate.
Rationale: .It .is .important .to .assess .the .patient's .apical-radial .pulse .rate .because
.PVCs .often .do .not .generate .a .sufficient .ventricular .contraction .to .result .in .a
.peripheral .pulse, .which .can .lead .to .a .pulse .deficit. .- .CORRECT .ANSWER-During
.change-of-shift .report, .the .nurse .learns .that .a .patient .with .a .large .myocardial
.infarction .has .been .having .frequent .PVCs. .When . monitoring .the .patient .for .the
.effects .of .PVCs, .the .nurse .will .check .the . patient's
"You .had .a .serious .abnormal .heart .rhythm, .which .treatment .was .able .to
.reverse."
Rationale: .This .response .honestly .describes .what .happened .to .the .patient .while
.avoiding .unnecessarily .increasing .the .patient's .anxiety .level. .More .information
.may .be .given .by .the . nurse .if .the .patient .asks .further .questions. .- .CORRECT
.ANSWER-A .patient .who .has .been .successfully .resuscitated .after .developing
.ventricular .fibrillation .asks .the .nurse .about .what .happened. .The .most
.appropriate .response .by .the .nurse .is,
stimulate .a .heart .beat .if .the .patient's .own .heart .rate .drops .too .low.
Rationale: .The .permanent .pacemaker .will .discharge .when .the .ventricular .rate
.drops .below .the .set .rate. .- .CORRECT .ANSWER-A .patient .has .a .permanent
.pacemaker .inserted .for .treatment .of .chronic .atrial .fibrillation .with .slow
.ventricular .response. .The .nurse .teaches .the .patient .that .the .pacemaker .will
"I .won't .lift .the .arm .on .the .pacemaker .side .up .very .high .until .I .see .the .doctor."
Rationale: .The .patient .is .instructed .to .avoid .lifting .the .arm .on .the .pacemaker
.side .above .the .shoulder .to .avoid .displacing .the .pacemaker .leads. .- .CORRECT
A+ Graded (2025)
PR .interval. .
Rationale: .The .PR .interval .represents .depolarization .of .the .atria, .AV .node,
.bundle .of .His, .bundle .branches, .and .the .Purkinje .fibers, .up .to .the .point .of
.depolarization .of .the .ventricular .cells. .- .CORRECT .ANSWER-In .analyzing .a
.patient's .electrocardiographic .(ECG) .rhythm .strip, .the .nurse .uses .the .knowledge
.that .the .time .of .the .conduction .of .an .impulse .through .the . Purkinje .fibers .is
.represented .by .the
use .the .3-second .markers .to .count .the .number .of .QRS .complexes .in .6 .seconds
.and .multiply .by .10.
Rationale: .This .is .the .quickest .way .to .determine .the .ventricular .rate .for .a .patient
.with .a .regular .rhythm. .- .CORRECT .ANSWER-When . needing .to .estimate .the
.ventricular .rate .quickly .for .a .patient .with .a .regular .heart . rhythm .using .an .ECG
.strip, .the .nurse .will
40-60 .
If .the .SA .node .fails .to .discharge, .the .junction .will .automatically .discharge .at .the
.normal .junctional .rate .of .40 .to .60. .- .CORRECT .ANSWER-A .patient .has .a
.junctional .escape .rhythm .on .the . monitor. .The .nurse .would .expect .the .patient .to
.have .a .pulse .rate .of .____ .beats/min.
Obtain .further .information .about .possible .causes .for .the .heart .rate.
Rationale: .The .patient .has .sinus .tachycardia, .which .may .be .caused .by .multiple
.stressors .such .as .pain, .dehydration, .or .myocardial .ischemia; .further
.assessment .is .needed .before .determining .the .treatment. .- .CORRECT .ANSWER-
A .patient .who .is .complaining .of .a ."racing" .heart .and .nervousness .comes .to .the
.emergency .department. .The .patient's .blood .pressure .(BP) .is .102/68. .The .nurse
.places .the .patient .on .a .cardiac .monitor .and .obtains .the .following .ECG .tracing. .
Which .action .should .the .nurse .take .next?
MCL1
Rationale: .Leads .II .and .MCL1 .are .the .best .leads .for .visualization .of .P .waves,
.which .reflect .atrial .activity. .- .CORRECT .ANSWER-A .patient .has .a .dysrhythmia
.that .requires .careful .monitoring .of .atrial .activity. .Which .lead .will .be .best .to .use
.for .continuous .monitoring?
,ventricular .tachycardia.
Rationale: .The .absence .of .P .waves, .wide .QRS, .rate .>150, .and .the .regularity .of
.the .rhythm .indicate .ventricular .tachycardia. .- .CORRECT .ANSWER-The .nurse
.obtains .a .monitor .strip .on .a .patient .admitted .to .the .coronary .care . unit .with .a
.myocardial .infarction .and .makes .the .following .analysis: .P .wave . not .apparent;
.ventricular .rate .162, .R-R .interval .regular; . PR .interval .not .measurable; .and .QRS
.complex .wide .and .distorted, .QRS .duration .0.18 .second. .The .nurse .interprets .the
.patient's .cardiac .rhythm .as
every .other .QRS .complex .is .wide .and .starts .prematurely.
Rationale: .Ventricular .bigeminy .describes .a .rhythm .in .which .every .other .QRS
.complex .is .wide .and .bizarre .looking. .- .CORRECT .ANSWER-The .nurse
.determines .that .a .patient .has .ventricular . bigeminy .when .the .rhythm .strip
.indicates .that
document .the .finding .and .continue .to .monitor .the .patient
.Rationale: .First-degree .atrioventricular .(AV) .block .is .asymptomatic .and .requires
.ongoing .monitoring .because .it .may .progress .to .more .serious .forms .of .heart
.block. .- .CORRECT .ANSWER-A .patient .has .a .normal .cardiac .rhythm .strip .except
.that .the .PR .interval .is .0.34 .seconds. .The .appropriate .intervention .by .the . nurse .is
.to
hypokalemia.
Rationale: .Hypokalemia .increases .the .risk .for .ventricular .dysrhythmias .such .as
.PVCs, . ventricular .tachycardia, .and .ventricular .fibrillation. .- .CORRECT .ANSWER-
A .patient .with .diabetes .mellitus .is .admitted .unresponsive .to .the .emergency
.department .(ED). .Initial .laboratory .findings .are .serum .potassium .2.8 .mEq/L .(2.8
.mmol/L), .serum .sodium .138 .mEq/L .(138 .mmol/L), .serum .chloride .90 .mEq/L .(90
.mmol/L), .and .blood .glucose .628 .mg/dl .(34.9 .mmol/L). .Cardiac .monitoring .shows
.multifocal .PVCs. .The .nurse .understands .that .the .patient's .PVCs .are .most .likely
.caused .by
administer .IV .antidysrhythmic .drugs .per .protocol.
Rationale: .The .burst .of .sustained .ventricular .tachycardia .indicates .that .the
.patient .has .significant .ventricular .irritability, .and .antidysrhythmic .medication
.administration .is .needed .to .prevent .further .episodes. .- .CORRECT .ANSWER-The
.nurse .reviews .data .from .the .cardiac .monitor .indicating .that .a .patient .with .a
.myocardial .infarction .experienced .a .50-second .episode .of .ventricular
.tachycardia .before .a .sinus .rhythm .and .a . heart .rate .of .98 .were .re-established.
.The .most .appropriate .initial .action .by .the . nurse .is .to
third-degree .AV .block.
Rationale: .The .inconsistency .between .the .atrial .and .ventricular .rates .and .the
.variable .PR .interval .indicate .that .the .rhythm .is .third-degree .AV .block. .-
.CORRECT .ANSWER-A .patient .experiences .dizziness .and .shortness .of .breath .for
.several .days. .During .cardiac .monitoring .in .the .ED, .the .nurse .obtains .the
.following .ECG .tracing. .The .nurse .interprets .this .cardiac .rhythm .as
increase .in .the .patient's .heart .rate.
, Rationale: .Atropine .will .increase .the .heart .rate .and .conduction .through .the .AV
.node. .- .CORRECT .ANSWER-A .patient .with .myocardial .infarction .develops
.symptomatic .hypotension. .The .monitor .shows .a .type .1, .second-degree .AV .block
.with .a .heart .rate .of .30. .The .nurse .administers .IV .atropine .as .prescribed. .The
.nurse .determines .that .the .drug .has .been . effective .on .finding .a(n)
anticoagulant .therapy .with .warfarin .(Coumadin).
Rationale: .Atrial .fibrillation .therapy .that .has .persisted .for .more .than .48 .hours
.requires .anticoagulant .treatment .for .3 .to .4 .weeks .before .attempting
.cardioversion; .this .is .done .to .prevent .embolization .of .clots .from .the .atria .-
.CORRECT .ANSWER-A .patient .with .dilated .cardiomyopathy .has .an .atrial
.fibrillation .that .has .been .unresponsive .to .drug .therapy .for .several .days. .The
.nurse .anticipates .that .further .treatment .of .the .patient .will .require
start .basic .cardiopulmonary .resuscitation .(CPR).
Rationale: .The .patient's .rhythm .and .assessment .indicate .ventricular .fibrillation
.and .cardiac .arrest; .therefore, .the .initial .actions .include .calling .for .help, .and
.initiating .CPR .until .defibrillation .is .possible. .- .CORRECT .ANSWER-The .nurse
.hears .the .cardiac .monitor .alarm .and . notes .that .the .patient .has .a .cardiac .pattern
.of .undulations .of .varying .contours .and .amplitude .with .no .measurable .ECG
.pattern. .The .patient .is .unconscious .with .no .pulse .or .respirations. .After .calling
.for .assistance, .the .nurse .should
apical .radial .heart .rate.
Rationale: .It .is .important .to .assess .the .patient's .apical-radial .pulse .rate .because
.PVCs .often .do .not .generate .a .sufficient .ventricular .contraction .to .result .in .a
.peripheral .pulse, .which .can .lead .to .a .pulse .deficit. .- .CORRECT .ANSWER-During
.change-of-shift .report, .the .nurse .learns .that .a .patient .with .a .large .myocardial
.infarction .has .been .having .frequent .PVCs. .When . monitoring .the .patient .for .the
.effects .of .PVCs, .the .nurse .will .check .the . patient's
"You .had .a .serious .abnormal .heart .rhythm, .which .treatment .was .able .to
.reverse."
Rationale: .This .response .honestly .describes .what .happened .to .the .patient .while
.avoiding .unnecessarily .increasing .the .patient's .anxiety .level. .More .information
.may .be .given .by .the . nurse .if .the .patient .asks .further .questions. .- .CORRECT
.ANSWER-A .patient .who .has .been .successfully .resuscitated .after .developing
.ventricular .fibrillation .asks .the .nurse .about .what .happened. .The .most
.appropriate .response .by .the .nurse .is,
stimulate .a .heart .beat .if .the .patient's .own .heart .rate .drops .too .low.
Rationale: .The .permanent .pacemaker .will .discharge .when .the .ventricular .rate
.drops .below .the .set .rate. .- .CORRECT .ANSWER-A .patient .has .a .permanent
.pacemaker .inserted .for .treatment .of .chronic .atrial .fibrillation .with .slow
.ventricular .response. .The .nurse .teaches .the .patient .that .the .pacemaker .will
"I .won't .lift .the .arm .on .the .pacemaker .side .up .very .high .until .I .see .the .doctor."
Rationale: .The .patient .is .instructed .to .avoid .lifting .the .arm .on .the .pacemaker
.side .above .the .shoulder .to .avoid .displacing .the .pacemaker .leads. .- .CORRECT
